The Next Generation Network (NGN) is currently a hot research topic in the field of communication standard, which adopts the IP packet technology as a bearer network technology, and integrates fixed communication and mobile communication so as to provide more multimedia services, such as emerging services with real-time requirements like IPTV, Video conference, multimedia distance learning, video on demand, and so on. These services require that a communication network should provide efficient end-to-end Quality of Service (QoS) support, therefore, providing end-to-end QoS has become one of the core issues of the NGN.
The International Telecommunication Union-Telecommunications standardization sector (ITU-T) is a telecom sector of the International Telecommunication Union (ITU), which formulated the standard related to resource and admission control. In a latest Resource and Admission Control Function (RACF) draft released by the ITU-T, the functional framework of the RACF is provided, as shown in FIG. 1, the RACF is consisted of two parts, i.e. Policy Decision Functional Entity (PD-FE) and Transport Resource Control Functional Entity (TRC-FE).
The PD-FE makes preliminary QoS resource decision based on media stream session information (obtained from a Service Control Function (SCF) through Rs interface) and transmission resource subscription information (obtained from a Network Attachment Control Function (NACF) through Ru interface), then interacts with the TRC-FE to confirm whether there are enough QoS resources, after which makes a final admission decision and transmits the decision to a PE-FE to execute. In other words, the PD-FE relates neither to the transmission technology nor to the SCF, the PD-FE makes the final decision of resource and admission control based on Network policy rules, the service information provided by the SCF, the transport layer subscription information provided by the NACF, and the resource availability decision result provided by the TRC-FE.
The TRC-FE is not related to services but related to the transmission technology. The TRC-FE is responsible for collecting and maintaining transmission network information and resource status information. After receiving a resource request from the PD-FE, the TRC-FE executes resource-based admission control according to the QoS, priority needs, resource availability information and policy rules related to transmission.
Besides, the transport layer in the home network is generally consisted of a Policy Enforcement Functional Entity (PE-FE) and a Transport Resource Enforcement Functional Entity (TRE-FE), wherein the PE-FE is a packet-to-packet gateway, and may be located between a Customer Premises Network (CPN) and an access network, between an access network and a core network, or between different operator's networks. The PE-FE is a key node supporting dynamic QoS control, port address translation control and Network Address Translator (NAT) traversing, and mainly for executing policy control (Gating, bandwidth, traffic classification and marking, traffic shaping, two-layer and three-layer QoS mapping, collecting and reporting resource usage situation and the like) under the guidance of the PD-FE. The TRE-FE executes the transport resource policy rules transmitted by the TRC-FE. The range and function of the TRE-FE as well as the Rn interface need further study, which are not within the study scope of stage R2.
The Customer Premises Network (CPN) includes a Home network Policy Decision Functional Entity (HPD-FE), which executes policy decision in the range of the home network; the CPN further includes a CPN Gateway Policy Enforcement Functional Entity (CGPE-FE), which executes policy rules transmitted by the HPD-FE or PD-FE.
Now, the demands of users for home security and entertainment services, such as video surveillance, network gaming, P2P transmission and IPTV and the like, are increasingly strong. To effectively support this kind of services with high speed, high service requirements and high security, an operator needs to perform QoS control on the home network. A home gateway is the essential core component of the home network, which connects the network devices of home with external network, and is a physical interface interconnects a home internal network with all external networks.
In a non-nomadic/non-roaming scene, the PD-FE of a RACF controls the CGPE-FE of a CPN through the Rh interface or controls a HPD-FE through the Rh′ interface, so as to control the home network.
FIG. 2 shows a schematic diagram of the resource and admission control of a home network under the wholesale scene in the related art. as shown in FIG. 2, in the wholesale scene, an NGN wholesale service provider takes the network level as an infrastructure and opens to many NGN retail service providers in the mode of wholesale and provides no service, while the NGN retail service provider provides various services. When a user is in the wholesale scene, the user may use the network access of the NGN wholesale service provider to access the network and enjoy the services provided by the NGN retail service provider.
However, in the wholesale scene shown in FIG. 2, the SCF belongs to the NGN retail service provider, and the PD-FE of the NGN retail service provider interacts with a CGPE-FE of a CPN through the Rh interface, so as to realize the resource and admission control on the home network. Because the CGPE-FE only has a policy enforcement function without a policy decision function, the CGPE-FE, after receiving policy rules from the PD-FE of the NGN retail service provider, installs policy rules directly without performing authorization check and policy control. In this case, if a malicious request is received, the CGPE-FE will execute a malicious policy. Moreover, since many NGN retail service providers may share a certain home gateway, therefore, in the case that the RACFs of different NGN retail service providers control the CGPE-FE simultaneously, resource control errors such as resource desynchrony or resource inconsistence and the like may occur, which is not conducive to the stability of a system.